Yes, there is a complex caves system that comunicates 3 exterior sides with church's inside, creating an alternative flow inside-outside. Hope can be seen here:
[Blocked Image: http://img202.imageshack.us/img202/5329/lostvalley01272hc.th.jpg]
Think I'm the first doing such complex one single mesh map in source engine. There are nodraws to hide visibility, but thats fast compile.